SQL - Partition restarted based on a column value

Question

I need to create a new column that restarts at every 0 value of Column Repeated Call of each Customer_ID:

+-------------+---------+----------------------+---------------+
| Customer_ID | Call_ID | Days Since Last Call | Repeated Call |
+-------------+---------+----------------------+---------------+
|           1 |       1 | Null                 |             0 |
|           1 |       2 | 45                   |             0 |
|           1 |       3 | 0                    |             1 |
|           1 |       4 | 0                    |             1 |
|           1 |       5 | 0                    |             1 |
|           1 |       6 | 48                   |             0 |
|           1 |       7 | 1                    |             1 |
|           2 |       8 | Null                 |             0 |
|           2 |       9 | 1                    |             1 |
+-------------+---------+----------------------+---------------+

In to something like this:

+-------------+---------+----------------------+---------------+-------------+
| Customer_ID | Call_ID | Days Since Last Call | Repeated Call | Order_Group |
+-------------+---------+----------------------+---------------+-------------+
|           1 |       1 | Null                 |             0 |           1 |
|           1 |       2 | 45                   |             0 |           2 |
|           1 |       3 | 0                    |             1 |           2 |
|           1 |       4 | 0                    |             1 |           2 |
|           1 |       5 | 0                    |             1 |           2 |
|           1 |       6 | 48                   |             0 |           3 |
|           1 |       7 | 1                    |             1 |           3 |
|           2 |       8 | Null                 |             0 |           1 |
|           2 |       9 | 1                    |             1 |           1 |
+-------------+---------+----------------------+---------------+-------------+

Appreciate your suggestion, thanks!

Answer 1

You can use SUM() window function:

select t.*,
  sum(case when Repeated_Call = 0 then 1 else 0 end) 
  over (partition by Customer_ID order by Call_Id) Order_Group 
from tablename t

See the demo (for MySql but it is standard SQL).
Results:

| Customer_ID | Call_ID | Days Since Last Call | Repeated_Call | Order_Group |
| ----------- | ------- | -------------------- | ------------- | ----------- |
| 1           | 1       |                      | 0             | 1           |
| 1           | 2       | 45                   | 0             | 2           |
| 1           | 3       | 0                    | 1             | 2           |
| 1           | 4       | 0                    | 1             | 2           |
| 1           | 5       | 0                    | 1             | 2           |
| 1           | 6       | 48                   | 0             | 3           |
| 1           | 7       | 1                    | 1             | 3           |
| 2           | 8       |                      | 0             | 1           |
| 2           | 9       | 1                    | 1             | 1           |

Answer 2

You can calculation every 0 value in column Repeated Call (for each customer) using window analytic function COUNT with ROWS UNBOUNDED PRECEDING:

SELECT *, 
COUNT(CASE WHEN  Repeated Call=0 THEN 1 ELSE NULL END )OVER(PARTITION BY Customer_ID 
ORDER BY Call_ID ROWS UNBOUNDED PRECEDING)Order_Gr FROM Table